Last year, a security researcher was forced to cancel his talk scheduled for two hacker conferences about weaknesses in ATM software after the ATM vendor complained.

This year the talk is back on the agenda for Black Hat and Defcon, which run Wednesday and Thursday, and Friday through Sunday, respectively, in Las Vegas.

"I've always liked the scene in "Terminator 2" where John Connor walks up to an ATM, interfaces his Atari to the card reader and retrieves cash from the machine. I think I've got that kid beat," Barnaby Jack, who works for IOActive, wrote in the description for his presentation, which is titled "Jackpotting Automated Teller Machines Redux."